This invention relates to copending U.S. application (IR 6869) filed on even date herewith which describes unit dose fabric softening compositions comprising a water soluble container wherein there is disposed a fabric softener composition comprised of at least one amine fabric softening active compound.
This invention relates to fabric softener compositions containing an amine fabric softening active compound. More particularly, this invention relates to fabric softening compositions which are particularly effective for softening fabrics in the wash cycle of a laundering operation concomitant to promoting the delivery of perfume to the fabric surface.
Compositions containing quaternary ammonium salts or imidazolinium compounds having at least one long chain hydrocarbyl group are commonly used to provide fabric softening benefits when used in a laundry rinse operation. Numerous patents have been issued for these types of compounds and compositions.
More recently, however, in view of concerns for the environmental safety (e.g., biodegradability) of the quaternary compound softeners, as well as limits in the amounts of these cationic compounds which can be stably incorporated into the more convenient to use liquid formulations, there have been many proposals for partial or total replacements for the conventional xe2x80x9cquatxe2x80x9d fabric softeners which are exemplified by dimethyl distearyl (or ditallow) ammonium chloride and various imidazolinium compounds.
For instance in GB 2,032,479A (corresponding to EP 038862) assigned to Albright and Wilson Ltd., water dispersible unquaternized hydroxyalkyl diamidoamine compounds are described in formula
RNH((CH2)nNR)mR
wherein an average of from 20% to 80% of the R groups are C12 to C22 acyl, at least 20% of the R groups are xe2x80x94CH2CH2OH or xe2x80x94CH2CHOHCH3 or mixtures of these groups, and any other R group is hydrogen, n is 2 or 3 and m is an integer of from 2 to 5, are provided as mobile pastes in the presence of lower alkanol solvents. This is stated to be in contrast to partially neutralized unquaternized diamidoamine which, while providing highly effective fabric softening properties, are too viscous even when diluted in the lower alkanol solvents for convenient handling.
U.S. Pat. No. 5,154,838 (corresponding to EP 0459211A2) to Yamamura, et al. (assigned to Kao Corp.) discloses an aqueous liquid softener composition based on an amidoamine compound which is the condensation reaction product of a di- or tri-amine of formula (I)
R1NH(CmH2mNH)nH
with a fatty acid of formula (II) 
wherein R1 represents a straight or branched chain, saturated or unsaturated hydrocarbon group having 8 to 24 carbon atoms, R2 represents a straight or branched, saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, m represents 2 or 3, and n is 1 or 2. These compounds, which are neither hydroxylated or ethoxylated, are noted to have high dispersibility in rinse water, especially when the amido amine compound is used in the form of its neutral salt.
In U.S. Pat. No. 5,133,885 to Contor, et al. assigned to Colgate-Palmolive Co., fabric softening compositions are described which are aqueous dispersions of a fatty acid ester quat of formula 
wherein one or two R groups represent an aliphatic ester residue of from 12 to 30 carbon atoms of formula xe2x80x94(CH2xe2x80x94)nOCOR4 and the remaining R groups represent lower aliphatic, aralkyl or hydroxyalkyl groups, Xxe2x88x92 is an anion and xe2x80x9caxe2x80x9d represents the ionic valence of the anion, and a fatty acid amido amine softener of formula 
where R1 is a C12 to C30 alkyl or alkenyl group, R2 represents R1, R1CONH(CH2)m or CH2CH2OH; R3 represents hydrogen, methyl, or (CH2CH2O)pH, m is a number of 1 to 5 and p is a number of 1 to 5, at a weight ratio of ester quat to amido amine of from 10:1 to 1:10.
U.S. Pat. Nos. 5,433,869 and 5,476,598, assigned to Colgate-Palmolive Company, disclose liquid rinse cycle softening compositions containing a fatty amido amine compound in the form of an acid complex as the principal softening component.
While these and many other proposals are known for improved fabric softening compositions, nevertheless, further improvements are desired to provide a softening composition capable of providing efficient softening in the wash cycle of a household washing machine concomitant with promoting perfume delivery to the fabric surface.
The present invention provides a wash cycle fabric softener composition which is dispersible in the wash water of a laundering operation, said fabric softener composition comprising, by weight:
(a) from about 48% to about 82% of at least one amine fabric softening active compound;
(b) from about 0.1% to about 18% of an alpha hydroxy aliphatic acid selected from the group consisting of citric acid, lactic acid, glycolic acid and mixtures thereof, wherein the amine fabric softening active compound at least partially reacts in situ with the alpha hydroxy acid to form an amine salt of the alpha hydroxy acid;
(c) from about 0.5% to about 6% of a cationic surfactant;
(d) from about 0% to about 9% of a cationic softener;
(e) from about 4% to about 14% of a perfume; and
(f) less than about 6% of water.
Another embodiment of a wash cycle fabric softener composition in accordance with the invention comprises, by weight:
(a) from about 50% to about 70% of at least one amine fabric softening active compound;
(b) from about 13% to about 23% of an alpha hydroxy acid selected from the group consisting of citric acid and lactic acid and mixtures thereof, wherein the amine fabric softening active compound at least partially reacts in situ with the alpha hydroxy acid to form an amine salt of the alpha hydroxy acid;
(c) from about 0.5% to about 6% of a cationic surfactant;
(d) from about 3% to about 12% of a perfume; and
(e) less than about 9% of water.
In accordance with another embodiment of a wash cycle fabric softener composition of the invention, there is provided a composition comprising, by weight:
(a) from about 28% to about 42% of at least one amine fabric softening active compound;
(b) from about 5% to about 15% of an alpha hydroxy acid selected from the group consisting of citric acid and lactic acid and mixtures thereof, wherein the amine fabric softening active compound at least partially reacts in situ with the alpha hydroxy acid to form an amine salt of the alpha hydroxy acid;
(c) from about 0.1% to about 4% of a cationic surfactant;
(d) from about 4% to about 12% of a perfume;
(e) from about 25% to about 50% of an alkali metal sulfate such as sodium sulfate; and
(f) less than about 5% of water.
The term xe2x80x9cfabric softenerxe2x80x9d is used herein for purposes of convenience to refer to materials which provide softening and/or conditioning benefits to fabrics in a home or automatic laundering machine or in a hand wash operation as well as effectively delivering fragrance to the fabric being cleaned.
The fabric softener compositions of the invention are preferably comprised of one or more fabric softening agents and a perfume.
In accordance with the process aspect of the invention there is provided a process for softening or conditioning laundry which comprises contacting the laundry in the wash water with an effective amount of the fabric softener compositions of the invention defined herein.
As used herein and in the appended claims the term xe2x80x9cperfumexe2x80x9d is used in its ordinary sense to refer to and include any non-water soluble fragrant substance or mixture of substances including natural (i.e., obtained by extraction of flower, herb, blossom or plant), artificial (i.e., mixture of natural oils or oil constituents) and synthetically produced substance) odoriferous substances. Typically, perfumes are complex mixtures of blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of essential oils (e.g., terpenes) such as from 0% to 80%, usually from 10% to 70% by weight, the essential oils themselves being volatile odoriferous compounds and also serving to dissolve the other components of the perfume.
In the present invention the precise composition of the perfume is of no particular consequence to softening performance so long as it meets the criteria of water immiscibility and having a pleasing odor. Naturally, of course, especially for softening compositions intended for use in the home, the perfume, as well as all other ingredients, should be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc.